MONTPELIER — The local firefighters union, along with its state affiliate, sued the city last week.

Firefighters are seeking to obtain additional city documents related to the proposed elimination of one firefighter position. Professional Fire Fighters of Vermont Inc. President Matt Vinci said the information could reveal whether the city has plans for even deeper cuts to the city’s fire force in future years.

“We feel the firefighters and the public should know what’s been discussed. We don’t know why they don’t want a transparent process,” Vinci said Tuesday.

The Professional Fire Fighters of Vermont and its local affiliate, the International Association of Fire Fighters Local 2287 — the Montpelier firefighters union — filed the lawsuit Feb. 11 in Washington County Superior Court, asking a judge to review and release 23 city documents. The documents are mainly electronic communications beyond what the city has already released to the organizations.

City officials, however, say releasing the records could set a harmful precedent. Mayor John Hollar said that if certain types of documents are subject to disclosure, city officials might not have as candid discussions as necessary for the development of successful policies and plans.

Vinci said the local and state firefighters unions are seeking the documents before Town Meeting Day, when residents will vote on the city budget. Union officials have said the proposed cut — of the position of an on-duty lieutenant who is retiring — will mean increased safety risks for the community and for firefighters.

The city currently has four nights, from 5 p.m. to 8 a.m., when three-person crews are on duty. The city’s new staffing plan calls for one more night when that’s the case.

“It’s a risk that we’ve accepted and a risk we’ve been able to manage,” Montpelier Fire Chief Bob Gowans said Tuesday, a statement expressed by city officials on his behalf during the budget development process.

By comparison, a four-person crew is part of a standard adopted by many states, including Vermont, that calls for two responders to be stationed outside a building when two other responders go into the structure during certain emergency situations. If the standard is violated, municipal fire departments can face fines up to $7,000 per incident, and as much as $70,000 for woeful or repeat violations, subject to Occupational Safety and Health Administration rules, said Steve Monahan, director of Vermont’s Workers’ Compensation and Safety Division.

Monahan said the standard is not a staffing requirement but a measure designed to protect the firefighters in the event of equipment malfunctions or disorientation. The responders outside monitor those inside and are prepared to rescue them if needed.

“Before you send people in to fight a fire from the inside, you would have to meet this requirement at a minimum,” Monahan said. “It’s not about someone who sees a person on the second floor and charges in to rescue them.”

If the rescue of a person is involved, the four-person crew requirement does not need to be met, fire officials at both the local and state levels said. Other fire departments can provide assistance to meet the requirement. And the provision does not apply to volunteer fire departments, Monahan said.

Gowans, the Montpelier fire chief, said that in 2012 there were 52 overlapping calls, a number expected to slightly increase. Overlapping calls occur when fire officials respond to one emergency call and then are needed at a second call.

If staffing levels are limited, crews can’t handle overlapping calls, Local 2287 President Jake Larrabee, a lieutenant with the city’s Fire Department, said Tuesday. Gowans said that to avoid that possibility, the city would have to hire three or four firefighters, but even that wouldn’t be a guarantee and another fire department could be needed to assist.

Larrabee and another firefighter gave a presentation to the City Council in January, describing studies that are said to have found a drastic difference in the relative effectiveness and safety of four-person and three-person crews.

“What it’s doing is further diminishing our ability to safely and effectively do our job,” Larrabee said of the city proposal to reduce the fire force by the single position.

Many of the documents that union officials requested are electronic communications between Hollar and City Manager William Fraser. In responding to the firefighters’ initial request for documents, the city withheld some that it claimed were exempt, including interdepartmental or intradepartmental communications preliminary to the setting of a budget policy, budget action or presentation.

Other exemptions cited included provisions in the state’s public records law involving documents dealing with personnel and personal files, which could relate to an individual’s private finances or health information.

In responding to the firefighters’ Jan. 25 records request, the city first released some of the documents before later releasing 42 more documents, according to the court filing.

Larrabee said that change shows the city contradicted itself. Union officials said they’re fairly confident a judge will rule in their favor.

Hollar said the legal costs to the city in this matter are minor. The city expects a judge to make a determination without ordering that testimony from both sides be heard.